Adolf Hitler visiting Malnava (Latvia), at HQ of Army, Group North

As it is mentioned in 2nd edition of Peter Hoffmann's book Hitler's Personal Security. Protecting the Führer 1921-1945, a list of Hitler's itinerary between September 39-April 45: 

"July 01-21 'Wolfschanze' 21 Korsovka, HQ Army Group North 21-31 'Wolfschanze'

Hitler made 1 day visit to Malnava, where General Staff of Eastern front (Group Nord) (Oberkommandos der Heeresgruppe Nord) was located.

Video from this visit

Photos of this visit is included in journal "Der Feldzug gegen die Sowietunion Krieg", 1941

Bunker of the staff was not demolished and is still preserved. It is located under local Karsava school and park buildings (Karsava school was former Karsava manor centre).

Army Group North (Heeresgruppe Nord) was a German strategic echelon formation, commanding a grouping of field armies during World War II. The army group was subordinated to the Oberkommando des Heeres (OKH), the German army high command, and coordinated the operations of attached separate army corps, reserve formations, rear services and logistics.

In preparation for Operation Barbarossa, Army Group North was reformed from Army Group C on 22 June 1941. Army Group North was commanded by Field Marshal Wilhelm Ritter von Leeb and staged in East Prussia, later in Latvia.

Its strategic goal was Leningrad, with operational objectives being the territories of the Baltic republics and securing the northern flank of Army Group Centre in Northern Russia between Western Dvina River and Daugavpils-Kholm Army Group boundary. On commencement of the Wehrmacht's (the German armed forces) Baltic offensive operation the Army Group deployed into Lithuania and northern Belorussia.

It served mainly in Baltic territories and north Russia until 1944.

Commander in Chief 22 June 1941: GFM Wilhelm Ritter von Leeb